Title page for ETD etd-10222009-124837

The determination of a dimensional spare out area for package closure placement

Degree

Master of Science

Department

Systems Engineering

Advisory Committee

Advisor Name

Title

Youngman, Roger R.

Committee Chair

Pfeiffer, Douglas G.

Committee Member

Pienkowski, Robert L.

Committee Member

Keywords

Packaging

Date of Defense

1994-05-13

Availability

restricted

Abstract

The risk of corn rootworm damage to continuously-grown corn was assessed in 32
fields from seven counties in Virginia in 1993 and 1994, Approximately 28% of the fields
examined had economic root damage in corn left untreated with a soil insecticide. In
addition, 19% of the fields overall had an economic loss in silage due to corn rootworm
damage.

A second study evaluated the effectiveness of using adult corn rootworm counts on
commercial Olson yellow sticky traps and ear-zone regions of corn plants to predict
subsequent damage to corn. Regression models for each sampling method were used to
calculate economic thresholds of 20 adults per trap per wk for the Olson trap and 0.3 adults
per stalk for the ear-zone visual count method. Adult counts on Olson traps obtained in
mid-Aug correctly predicted economic damage to com 81% of the time; and resulted in
only one serious error of failing to predict economic damage to corn. A sampling plan for
the use of Olson traps is suggested.

A third study investigated a possible sexual dimorphism in the elytra coloration
pattern of western corn rootworm, and compared the sex ratio of adults captured yellow
sticky traps with those obtained by aspiration. Striped and solid variations in elytra pattern
were found in both sexes of western corn rootworm; however, 98% of the adults that
exhibited the solid elytra pattern were male. The sex ratio of adults varied over time;
however, in all cases, sticky traps captured a significantly greater proportion of males
compared with aspiration.